Charge forming means



Filed Dec. 2, 1955 3 Sheets-Sheet 1 in R\ k v "5.5:. JUDh .1 W \O N M & \N \N AM k & fin. Q i \M ww N\ v R ZmflO NAN N 40 m \w N aw M? H 1 NM kw BY efi d ga 062M ATTORNEY June 23, 1959 u. DOLZA CHARGE FORMING MEANS I Filed D ec. 2, 1955 4 C1 '.FlLTER/ J p 29 6 I v FUEL FUEL TANK BUMP FILTER I FUEL FUEL TANK PUMP g9' w ib la ATTORNE Y June 23, 1959 J. DOLZA 2,891,527

CHARGE FORMING MEANS Filed Dec. '2, 1955 s Sheets-Sheet 3 IN VENT OR.

A TTORNEY Unite States Patent T g CHARGE FORMING MEANS John Dolza, Fenton, Mich, assignor to General Motors Corporation, Detroit, Mich, a corporation of Dela- .ware

Application December 2, 1955, Serial No. 550,587

17 Claims. (Cl. 123-119) The. present invention relates to internal combustion engines and more particularly to the charge forming means therefor.

In the operation of an internal combustion engine of the spark ignited variety, a combustible charge of air and fuel is supplied to the cylinders so as to be burned therein. This charge is normally formed outside of the cylinders by some suitable means such, for example, as afuel injection system having means for spraying the fuel into the air adjacent the engine cylinders. In order to maintain the correct proportions in the charge a fuel meteringmechanism may be provided that senses the fuel demands of the engine and causes metered fuel to be distributed in accordance with these demands. During certain engine operating conditions, for example deceleration of an automotive vehicle, the load will overrun or drive the engine at a speed in excess of the speed normally resulting from the throttle setting. During such conditions the fuel performs no useful work and is consequently wasted. In addition, the throttle valve is normally closed and the intake manifold vacuum is extremely high, thus impairing the burning of the fuel and causing a large amount of unburned hydrocarbons to appear in the exhaust system.

ltis now proposed to increase the fuel economy of the engine and reduce the amount of unburned hydrocarbons in the exhaust system -by eliminating the delivery of any fuel to. the engine during overrunning conditions. This is to'jbe accomplished by providing means for overriding the normal metering action of the metering mechanism by employing a speed responsive mechanism such as a governor that is interconnected with the throttle control. Thus whenever the speed of the engine is in excess of that normally produced by the throttle setting, the fuel flow willbe substantially eliminated. If desired, this same mechanism mayalso be effective to simultaneously completely open the throttle valve and allow fresh air to flow through the engine.

. -ln the three sheets of drawings:

Figure, l is a cross sectional view of an engine employing a fuel injection system embodying the present invention, the parts thereof being positioned for road load operation of the engine.

Figure 2 is a diagrammatic View of the fuel'injection system of Figure 1 with the parts thereof in position for an overrunning condition of the engine.

Figure 3 is a diagrammatic view similar to Figure 2 but showing the parts of the injection system in position for idle operation of the engine.

[Figure 4is a diagrammatic view of a fuel injection system employing another embodiment of the present invention, the parts thereof being positioned for road load operation of the engine,

f Figu re 5 is a diagrammatic view of the embodiment in Figure-4 but showing the parts thereof positioned for an overrunning condition of the engine.

Figure 6 is a diagrammatic view of the embodiment in I 2,891,527. Patented June 23, 1959 Figure 4 but showing the parts thereof in position for idle operation of the engine.

Referring to the drawings in more detail the present invention may be embodied in any suitable fuel injection system 10 for an internal combustion engine 12. In the present instance this engine 12 is of the so-called V-type having a pair of angularly disposed banks of cylinders 14 with pistons 16 therein operatively connected to the engine crankshaft 18. In order to change the cylinders 14 an induction system .20 and a fuel supply system 22 may be provided in the space between the two banks. The induction system 20 includes an intake 24 with a throttle valve 26 disposed therein, an intake manifold 28 and a plurality of intake passages 30 through the cylinder heads 32 interconnecting the manifold 28 with the engine cylinders 14. Although the fuel supply. system 22 may be of any suitable type in the present instance it is a fuel in jection system for spraying fuel from the nozzles 34 into the induction air in the passages 30 to form the charge adjacent the cylinders 14. By placing the nozzles adjacent the cylinders there will be a minimum wetting of the surfaces of the induction system. This injection system 10 includes a fuel tank 36, a transfer pump 38, a fuel filter 40 and a metering mechanism 42 responsive to the fuel demands of the engine 12 for regulating the amount of fuel distributed to the various cylinders 14. The metering mechanism 42 comprises a member such as a diaphragm 44 that is located in one wall of the manifold 28 to be responsive to the intake vacuum. The center of this diaphragm 44 is connected to a variable delivery metering pump 46 by an axially movable element 48 that has one end connected to the pump 46 so as to control the amount of fuel distributed from the pump 46. Since the pump 46 is driven by the engine 12 and the position of the movable element 48 regulates the fuel flow, the fuel will be properly metered to the engine cylinders. Although this system 22 operates essentially the same as the system disclosed and claimed in copending application Serial No. 511,954, Fuel Injection System filed May 31, 1955, in the name of John Dolza, it should be understood that the fuel injection system 22 may be modified in any desired manner without departing from the spirit of the invention.

In order to control the speed of the engine 12 an accelerator pedal 50 may be connected to the throttle 26 by means of a control linkage 52. Thus movement of the accelerator pedal 50 will vary the throttle setting and the amount of air flow to the engine 12. This, in turn,- will result in a change in the intake vacuum and a repositioning of the diaphragm 44 and the movable element 48 with a corresponding change in the metered fuel output from the pump 46. It should be noted that when the engine 12 is idling'the throttle valve 26 will be closed and the intake manifold vacuum will be high, there.- by drawing the movable element 48 downwardly and causing a minimum fuel output from the pump 46 and when the throttlevalve 26 is open, the intake vacuum will be low and the element 48 will be in an extended position with an increased fuel output from the pump' 46. Thus when the element 43 is in its lowest position the fuel output will be a minimum and when in its extended position, the fuel output will be a maximum.

If the engine 12 has been operating under some road load with the throttle 26 open and the throttle 26 is suddenly closed, the load will overrun the engine 12, i.e., the load will drive the engine 12 faster than the normal speed for the throttle setting. When this occurs the intake vacuum will be abnormally high and as a result the fuel may not bum properly and there may be a large amount of unburned hydrocarbons in the exhaust gases. Moreover, since the fu'eldoes not drive the load under these conditions, :it doesnot perform any useful work and is therefore wasted. In order to decrease the amount of unburned hydrocarbons in the exhaust and to increase the fuel economy of the engine 12, it is proposed to provide means for eliminating the fuel fiow during such overrunning conditions.

In order to accomplish this objective means are pro vided that will shut olf the fuel Whenever the speed of the engine exceeds the normal speed for the throttle setting. This means includes any suitable speed responsive means 54, for example, a fiyball governor that is driven by the engine 12. The governor 54 is connected to the center joint 56 of a toggle linkage 58 floating inside of a pair of guide rails 60, whereby movement of the governor 54 will bend this center joint 56 and change the over-all length of the toggle linkage 58. One end 62 of the toggle linkage 58 is connected to the throttle control 52 by an inclined link 64 that positions the toggle 58 in the guides 60. Thus when the accelerator .pedal 50 is in the idle position, the link 64 will be nearly in alignment with guides 69 and the toggle linkage 58 will be moved closest to the diaphragm 44 and when the accelerator 50 is in the open position, the toggle 58 will be moved away from the diaphragm 44. The other end 66 of the toggle linkage 58 is connected to the diaphragm 44 and/or the movable element 48 by a lost motion means or it may merely abut thereagainst. When the throttle 26 is closed and the engine speed is low, the governor 54 will cause the toggle linkage 58 to bend in the middle and shorten the over-all length thereof. Thus even though the link 64 moves the toggle 58 closest to the diaphragm 44, there will be a clearance space between the end of the toggle linkage 58 and the movable element 48. Thus the metering action of the diaphragrn 44, etc., will supply the normal fuel requirements of the engine 12. If the accelerator pedal 50 is moved to increase the speed, the link 64 will move to carry the toggle 58 in the guide 60 away from the diaphragm 44 and thus even though the governor 54 will straighten out the linkage 58, the end 66 thereof will still remain clear of the diaphragm 44 and leave it free to meter the fuel. However, if the speed of the engine 12 is high enough for the governor to straighten or partially straighten the toggle 58 and the throttle 26 is suddenly closed, the link 64 will force the toggle linkage 58 toward the daiphragm 44. If the load is overrunning the engine 12, the end 66 of the toggle 58 will then strike the center of the diaphragm 44 and depress it. This, in turn, will cause the movable element 48 to be forced into the minimum fuel position, thereby substantially eliminating any fuel being discharged from the injection system 22 into the engine 12. Thus it may be seen that whenever the speed of the engine 12 is greater than the normal speed for the throttle setting, the fuel flow will be reduced. However as the speed of the engine 12 decreases, the governor 54 will return towards the idle position and bend the toggle linkage 58. At approxi mately idle speed a clearance space appears between the end 66 of the toggle 58 and the diaphragm 44, thereby restoring the normal metering action.

The embodiment shown in Figures 4, 5 and 6 is similar to that in the first embodiment and it is also particularly adapted for use on a V-type engine 12. The induction system is the same with a throttle valve 26 operated by an accelerator pedal 50 and a control linkage 52 and is effective to determine the air flow. The fuel is also supplied by an injection system 22 having a variable delivery pump 46 controlled by a movable element 48 connected to a diaphragm 44 exposed to the intake vacuum. A toggle linkage 58 is disposed in a guide 60 with the center joint 56 connected to a governor 54 and one end thereof connected to the throttle control linkage 52 by a link .64. However, the other end 66 instead of being connected directly to the diaphragm 44 is connected to a servo control or transmitter unit 70. This unit 70 is then in turn connected to a suitable receiver or motor 72 in the metering mechanism and also if desired to a servo receiver or motor 74 connected to the throttle valve 26 in the induction inlet 24. During normal engine operating conditions the throttle valve 26 will be controlled by the accelerator pedal 50 and the fuel will be metered by the position of the diaphragm 44. For example, during idle operation the governor 54 will cause the toggle 58 to bend in the middle and even though the link 64 is parallel to the guides 60, the transmitter 74) will be inactive. As the accelerator pedal 56 moves to open the throttle 26 the link 64 will move the toggle 58 away from the transmitter 70 and then even though the governor 54 straightens the toggle 58, the servo transmitter 70 will remain inactive. However in the event the accelerator pedal 50 moves to close the throttle 26 while the engine 12 is running at a high speed, the toggle 58 will be moved to activate the servo transmitter 70. The receiver 72 in the metering mechanism will cause the metered fuel output of the pump 46 to decrease, thereby conserving the fuel essentially as before. However, in addition, a servo receiver 74 may also be connected to the throttle valve 26 so as to be actuated by the transmitter 7 it. Thus whenever the transmitter 70 shuts off the fuel flow, it will also simultaneously open the throttle valve 26 and allow uncharged fresh air to be freely pumped through the engine 12 and thereby materially increasing the fuel economy and substantially eliminating the presence of any unburned hydrocarbon in the exhaust system.

Since the nozzles are located adjacent the intake valves the charge will be formed adjacent the cylinders and there will be a minimum amount of Wetting of the sur faces in the induction system. Accordingly, the fuel cutoff will be fast acting, i.e., as soon as the fuel discharge from the nozzle stops, there will be no fuel available for the charge and conversely, as soon as the fuel flow commences, substantially all of the fuel will be immediately available for forming the charge.

It is to be understood that, although the invention has been described with specific reference to particular embodiments thereof, it is not to be so limited since changes and alterations therein may be made which are within the full intended scope of this invention as defined by the appended claims.

I claim:

1. Charge forming means for an internal combustion engine comprising an induction system having a throttle therein for controlling the flow of air into said engine, a fuel metering mechanism responsive to the fuel demands of said engine, and means responsive to the speed of said engine interconnected with said throttle for decreasing the fuel output from said metering mechanism independently of the position of said throttle setting whenever the speed of said engine exceeds the normal engine speed for the throttle setting.

2. A fuel supply system for an internal combustion engine having an induction system with a throttle therein for controlling the speed of said engine, said fuel supply system comprising a fuel metering mechanism responsive to the fuel demands of said engine, means responsive to the speed of said engine interconnected with said fuel metering mechanism for decreasing the output of fuel from said metering mechanism whenever the speed of said engine exceeds the normal engine speed for the throttle setting and means for continuously manually controlling the position of said throttle irrespective of said first means.

3. A fuel supply system for an internal combustion engine having an induction system with a throttle therein for controlling the speed of said engine, said fuel supply system comprising a fuel metering mechanism responsive to the fuel demands of said engine and including an element whose position controls the quantity of fuel delivered to the engine, and means responsive to the speed of said engine operatively interconnected with said throttle and said element for always moving said element toward the minimum fuel position whenever the speed of said engine exceeds some predetermined engine speed for the throttle setting.

4. Charge forming means for an internal combustion engine comprising an induction system having a throttle therein for controlling the flow of air into said engine, a fuel metering mechanism having a normally movable element responsive to the fuel demands of said engine, the position of said element being efiective to control the quantity of fuel delivered to said engine, and means responsive to' the speed of said engine operatively inter- .connected with said throttle and said element for allow ing normal metering movement of said element only when the speed of said engine is not in excess of the normal engine speed for the throttle setting.

5. In ancngine having a plurality of cylinders with an inductionsystem with a throttle therein for controlling the flow of air through said system and into said cylinders, a fuel system comprising the combination of a fuel meteringmechanism including a source of fuel and being responsive to the fuel demands of. said engine for distributing metered fuel to said cylinders, and means responsive to the speed of said engine and to the position of said throttle for decreasing the amount of said metered fuel distributed from said metering mechanism to said cylinders whenever the speed of said engine exceeds some predetermined speed for the throttle setting.

6. In an engine having a plurality of cylinders with an induction system with a throttle therein for controlling the flow of air through said system and into said cylinders, a fuel system comprising the combination of a fuel metering mechanism including a source of fuel and being responsive to the fuel demands of said engine for metering said fuel in proportion to said demands and including distributing means having a plurality of outlets located adjacent the engine cylinders for injecting said metered fuel therefrom, and means effective for decreasing the fuel flow from said distributing means whenever said engine is being overrun by the load.

7. In an engine having a plurality of cylinders, an induction system and a throttle therein for controlling the flow of air through said system and into said cylinders, a fuel injection system comprising the combination of a fuel metering mechanism responsive to the fuel demands of said engine and having a plurality of nozzles located for injecting fuel directly into said air adjacent said engine cylinders, and means responsive to the speed of said engine interconnected with said throttle for decreasing the flow of fuel from said nozzles whenever the speed of said engine exceeds the normal speed for the throttle setting.

8. In an engine having a plurality of cylinders, an induction system, a throttle in said system and means for manually actuating said throttle for controlling the flow of air through said system and into said cylinders, a fuel injection system comprising the combination of a variable delivery pump interconnected with a plurality of nozzles located for injecting fuel directly into said air adjacent the engine cylinders, a fuel metering mechanism responsive to the fuel demands of said engine operatively connected to said pump for normally regulating the output in proportion to said fuel demands, and means responsive to the speed of said engine operatively interconnected with said throttle and said pump for decreasing the delivery of said pump whenever the speed of said engine exceeds the normal speed for the throttle setting, said first mentioned means being effective to retain control of said throttle at all times.

9. A fuel supply system for an engine comprising a throttle for controlling the speed of said engine, a metering mechanism responsive to the fuel demands of said engine and including a source of pressurized fuel having a movable element whose position controls the quantity of metered fuel delivered to said engine, means responsive to the speed of said engine, said speed responsive means and said throttle being operatively interconnected with each other and with said metering mechanism by lost motion means for moving said movable element toward at position of minimum fuel delivery whenever the speed of said engine exceeds the normal speed for the throttle setting without changing the position of said throttle.

10. In an engine having an induction system with a throttle for controlling the flow of air into said engine, a fuel metering mechanism responsive to the quantity of air flowing through said induction system for metering the fuel in proportion thereto, said speed responsive means being adapted to oppose said metering mechanism and decrease the quantity of fuel flow from said metering mechanism as said speed of said engine increases, said throttle being operatively interconnected with said speed responsive means to deactivate said speed responsive means only as long as the speed of said engine is not in excess of the normal speed for the throttle setting.

,11. A fuel supply system for an engine having an induction system with a throttle for controlling the quantity of air flowing therethrough into the engine cylinders, said fuel supply system comprising the combination of a metering mechanism responsive to said quantity of air flow and having a movable element whose position controls the quantity of fuel mixed with said air, means responsive to the speed of said engine, lost motion means operatively interconnecting said speed responsive means with said movable element for moving said element toward the minimum fuel position with increases in engine speed, means interconnecting said throttle with said lost motion mechanism for retaining said lost motion means disconnected from said movable element to allow a nor mal supply of fuel only as long as said engine speed is not greater than the normal speed for the throttle setting.

12. A fuel supply system for an engine having an induction system with a throttle therein actuated by a throttle control linkage that continuously retains control over said throttle and is effective to regulate the flow of air into said engine, a fuel metering mechanism responsive to the quantity of air flowing through said induction system for metering the fuel in proportion thereto, said throttle control linkage and said speed responsive means being operatively interconnected with said metering mechanism by lost motion means to permit normal metering operations of said metering mechanism only as long as the speed of said engine does not exceed the normal speed of the engine for the throttle setting but being effective to override the action of said metering mechanism whenever the engine speed exceeds said normal speed.

13. A fuel supply system for an engine having an induction system with a throttle for controlling the flow of air through said system and into the engine cylinders, said fuel supply system comprising the combination of metering means responsive to the fuel demands of said engine, a variable delivery pump adapted to supply metered quantities of fuel to the various cylinders of said engine, said metering means being operatively connected to said pump for controlling the output of said pump in proportion to said fuel demands, means responsive to the speed of said engine operatively interconnected with said throttle and being effective to allow said metering mechanism to meter the fuel to said engine only when the speed of said engine is not in excess of the normal speed for the throttle setting.

14. The fuel supply system of claim 13 wherein said speed responsive means are also effective to decrease the output from said pump to substantially zero when said engine speed is in excess of said normal engine speed for the throttle setting.

15. In an engine having a plurality of cylinders with an induction system including a throttle for controlling the flow of air through said induction system into said cylinders, charge forming means comprising the combination of a fuel metering mechanism responsive to the fuel demands of said engine, a throttle control linkage for positioning said throttle and means responsive to the speed of said engine interconnected with said throttle control linkage for simultaneously opening said throttle and de creasing the fuel output from said metering mechanism whenever the speed of said engine exceeds the normal engine speed for said throttle control linkage setting.

16. The fuel supply system of claim 12 wherein said speed responsive means are also effective to simultaneously decrease the output from said pump to substantially zero when said engine speed is in excess of said normal engine speed for the throttle control linkage setting and to also move said throttle valve to the substantially fully opened position.

17. Charge forming means for an engine comprising an induction system having a throttle valve actuated by a throttle control linkage for regulating the flow of air through said induction system into said cylinders, a fuel supply system comprising a source of fuel under pressure, metering means adapted to control the supply of metered fuel from said source, means responsive to the speed of said engine, a normally inoperative servo control interconnected with said metering mechanism and Said throttle valve for simultaneously moving said throttle valve to the fully open position and stopping the flow of fuel, said normally inoperative servo control being operatively interconnected with said throttle control linkage and said speed responsive means to operate said servo control and thereby said throttle and said metering mechanism whenever the speed of said engine exceeds the normal speed for the throttle control linkage setting.

References Cited in the file of this patent UNITED STATES PATENTS 2,410,773 Chandler Nov. 5, 1946 2,410,774 Chandler Nov. 5, 1946 2,426,740 Mock Sept. 2, 1947 2,506,511 Mallory May 2, 1950 2,670,724 Reggio Mar. 2, 1954 OTHER REFERENCES Serial No. 281,826, Stieglitz .et a1. (A.P.C.), published May 18, 1943. 

